Oil field development in deep waters (water depths in excess of 400 m) requires that the producing wells be subsea, which implies that the wellhead and the Christmas tree shall be installed at the seabottom, a little above the seabed.
For economic reasons, the usual practice for said development has been to group various wells into one single structure, which is set at the seabottom. This structure is internationally known as a template. It includes, usually, a square or rectangular structure, in which a given number of wells is provided for, which are spaced between themselves according to a pattern established by the American Petroleum Institute--API, which sets 2.28 m (7.5 ft) as the minimum distance between well centers.
In the 70's the oil industry started adopting subsea well production and wet Christmas trees were developed. In the beginning, the production from various satellite wells was collected into one central manifold, being transported to floating storage or production units, or to fixed platforms.
With the discovery of major fields in water depths in excess of 400 m (current limit for divers' assistance), the oil industry started adopting subsea completion as an economically more feasible option for production development from said fields.
As a function of the specific characteristics of the producing reservoirs, the industry initiated the establishment of new template concepts, so as to make possible the existence of various producing wells in one single area and make production collecting to one single manifold easy, which could or not be incorporated into the template. The term template manifold refers to structures in which the manifold is associated to the template.